Overview Cognitively Ergonomic Route Background Directions Aspect of cognitively ergonomic route directions A Potential Basis for the � Landmarks OpenLS Navigation Service? � Direction concepts Stefan Hansen, Alexander Klippel, Kai-Florian Richter � Granularities and hierarchies Conclusions Outlook Aspects of Cognitively Ergonomic Background Route Directions Human beings are poorly equipped with spatial abilities (compared to other Landmarks species) � bad sense of direction poor eye sight Direction Concepts � useless sense of smell � One approach to overcome our limitations is the use of information Granularities / Hierarchies / Chunking technology On the other hand, evolution adapted us as all-rounders Human beings suffice in their environments � The 007 principle (Clark 1989) � The other approach therefore is to learn from human abilities to cope with their deficiencies � Learning efficiency from deficiency Requirement for information technology Ontologies and cognitive modelling (cognitive engineering) � Landmark Definitions Theoretical work by: Landmarks � Lynch (1960) � Siegel & White (1976) � Presson & Montello (1988) � Sorrows & Hirtle (1999) � Raubal & Winter (2002) � and others 1
General Question Addressed Prerequisite: Structure and Function Human interaction with the environment can be separated into How to integrate landmarks (automatically) into route structural and functional aspects directions to achieve cognitive ergonomics? Structural aspects are provided by the environment as such, e.g. intersection For example: Functional aspects are instantiated by our interaction with the environment short actions performed in the environment � easy to understand Both have an influence on the conceptualization and possibly the verbalization low cognitive load failsafe Route / Path, Structure / Function Movement / Event Perspective Wayfinding / route following is Structural perspective perspective Structural movement in constraining networks Origin Origin The primitives (events) of this movements are actions at decision points Functional perspective perspective Functional nonDP Destination Destination How are these events organized through the presence of a “landmark”? Klippel 2003 Some Examples Our Working Definition A landmark in our approach is an element in the environment with a contextual saliency that allows for structuring our knowledge with respect to movement / wayfinding in that environment. 2
Landmark Taxonomy Point Identified nonDP DP Landmark Elements Level Functionally 1 Element n Elements relevant for Conceptualized Area Point Area Line Point as Hansen, Richter, Klippel 2006 Point Point DP nonDP DP nonDP Object class level Street Name GSO Structure Turn Level DP+ DP- DP+ DP- DP+ DP- Turn level Geometric Geometric Area-Like Linear-Like Point-Like Area-Like Linear-Like Point-Like level level through (a)cross pass cross pass Spatial Spatial before at after relational level relational level Why is a Fine Grained Distinction Excursus: Spatial Prepositions Important? Applicability of projective terms and spatial Landau/Jackendoff (1993) and others prepositions about, above, across, after, against, along, alongside, amid(st), among(st), (a)round, at, atop, before, behind, below, beneath, beside, between, beyond, by, Relating modalities (language and graphics) down, during, for, from, in, inside, into, near, nearby, off, on, onto, opposite, out, out of, outside, over, past, since, through, throughout, till, to, toward, under, underneath, until, up, upon, via, with, within, without, Compounds left right Away from, Far from, In back of, In between, In front of, In line with, On top of, To the left of, To the right of, To the side of Verbs ... 3
n Elements Line Main distinction not identifying identifying last DP last DP � Whether or not the last element of a chunk is identified Geometric Area-Like Linear-Like Area-Like Linear-Like level Spatial along along after after relational level Landmark Taxonomy Area not identifying last DP Geometric Area-Like level Spatial around through relational level Class tree of the types of landmarks used: The Data Model All types of landmarks defined in our data model are derived from an abstract parent type comprising all basic information about a landmark Different types of landmarks are used in a polymorphic way Any type of landmark at the same place in an instruction can be used without the need of specifying which concrete type of landmark to use beforehand Based on the abstract parent type, all other types are developed according to the taxonomy of landmarks 4
To Summarize XLS Example Contextually salient route elements (aka landmarks) organize route knowledge It is important to characterize landmarks in a specific context such as movements in networks An extended Lynchonian approach seems to be fruitful A detailed taxonomy is the basis for a data model that captures aspects of cognitively ergonomic route directions Extra Geometric Functional Framework Direction Concepts Coventry, Prat-Sala, & Richards 2001 see also: Coventry & Garrod 2004 Structure and Function Structure and Function veer right veer right take the second exit fork right 5
Study 1: Research Question Answer 7 direction concepts (plus ‘back’ 180 What is an appropriate sector) 202.5 157.5 model for direction 135 225 concepts in city street combination of sectors and axes networks 247.5 112.5 sectors have different size 270 90 ‘front’ and ‘back’ plane are asymmetric 292.5 67.5 90 degree ‘left’ and ‘right’ demarcate ‘front’ from ‘back’ (Franklin et al. 1995) 45 315 337.5 22.5 0 ‘left’ and ‘right’ are symmetric Klippel et al. 2004 Study 2: Route directions are Towards a Systematic Characterization specified... by making the description more precise The complexity of a route direction to give is determined by “take a sharp right”; “go northwest” � by establishing spatial contrast to other options � the structure of the intersection “take the one furthest to the right” � • number of branches by explicitly mentioning non-intended candidates • spatial layout of intersection: typical or deviant � “don’t go straight but somewhat left” angles of branches by applying numerical ordering concepts the availability of disambiguating features � “second to the right” � • landmarks by anchoring actions to landmarks present at an intersection • salient spatial structures, e.g. T-intersections “turn right after the post office” � the action to be characterized � by using a structural concept to describe the nature of the • determines the change of direction intersection • distinguishes intended vs. competing objects � “fork right” Analysis of Three Intersections Empirical Study: Route Directions increasing complexity Intersection identified A non standard Complex intersection by Landmark direction change at a and non standard turn non standard Unambiguous Additional competing intersection landmark position branches Landmark position Standard turn at Landmark too far unambiguous but after standard intersection the turn Klippel et al. to appear 6
Structure and Function Summary Direction concepts in city street networks generally are represented as a combination of sectors and axes Sectors are sized differently The structure in which the action takes place influences the conceptualization / verbalization The aim is a systematic characterization of the complexity of an intersection (the interplay of structure and function) and the corresponding A B C D conceptualization / verbalization Chunking Chunking aims on reducing the cognitive load for the traveler by reducing the number of route directions given. Granularities and Hierarchies Several directions are subsumed in one single chunk. Two approaches to form chunks : • Spatial chunking (Klippel et al., 2003) • Segmentation (Dale et al., 2003) Two approaches Used techniques Spatial Chunking Segmentation Spatial chunking based on • Landmarks Reducing the number of Building up a hierarchy on the instructions given by route directions by subsuming unnecessary and segmenting the route and obvious directions in chunks. generating a summary for each segment. Chunked instructions are omitted. Segments can be unfold to access more detailed information. 7
Used techniques Used techniques Spatial chunking based on Spatial chunking based on • Landmarks • Landmarks • Point-landmarks • Point-landmarks • Line-landmarks Used techniques Used techniques Spatial chunking based on Spatial chunking based on • Landmarks • Landmarks • Point-landmarks • Point-landmarks • Line-landmarks • Line-landmarks • Area-landmarks • Area-landmarks • Number of chunked DPs Spatial chunking Cognitive OpenLS Used techniques Used techniques Spatial chunking based on Spatial chunking based on • Landmarks • Landmarks • Point-landmarks • Point-landmarks • Line-landmarks • Line-landmarks • Area-landmarks • Area-landmarks ROUTE • Number of chunked DPs • Number of chunked DPs 66 Segmentation based on Segmentation based on • Road-hierarchy • Road-hierarchy • Point-landmarks 8
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